What is the Greatest Common Factor of 15645 and 15657?

Greatest common factor (GCF) of 15645 and 15657 is 3.

GCF(15645,15657) = 3

We will now calculate the prime factors of 15645 and 15657, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 15645 and 15657.

How to find the GCF of 15645 and 15657?

We will first find the prime factorization of 15645 and 15657. After we will calculate the factors of 15645 and 15657 and find the biggest common factor number .

Step-1: Prime Factorization of 15645

Prime factors of 15645 are 3, 5, 7, 149. Prime factorization of 15645 in exponential form is:

15645 = 3¹ × 5¹ × 7¹ × 149¹

Step-2: Prime Factorization of 15657

Prime factors of 15657 are 3, 17, 307. Prime factorization of 15657 in exponential form is:

15657 = 3¹ × 17¹ × 307¹

Step-3: Factors of 15645

List of positive integer factors of 15645 that divides 15645 without a remainder.

1, 3, 5, 7, 15, 21, 35, 105, 149, 447, 745, 1043, 2235, 3129, 5215

Step-4: Factors of 15657

List of positive integer factors of 15657 that divides 15645 without a remainder.

1, 3, 17, 51, 307, 921, 5219

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 15645 and 15657. The biggest common factor number is the GCF number.
So the greatest common factor 15645 and 15657 is 3.

Also check out the Least Common Multiple of 15645 and 15657